For some years it has been known that the electrical conductivity of organic semiconductors can be strongly influenced by doping (electrical doping). Such organic semiconducting matrix materials can be formed either from compounds having good electron donor properties or from compounds having good electron acceptance properties. Strong electron acceptors, such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane (F4TCNQ) have been known for the doping of electron donor materials (HT) (U.S. Pat. No. 7,074,500). These produce what are known as “holes” in electron-donor-like base materials (hole transport materials) as a result of electron transfer processes, the conductivity of the base material being changed to a more or less significant extent as a result of the number and mobility of said holes. For example, N,N′-perarylated benzidines (TPD) or N,N′,N″-perarylated starburst compounds, such as the substance TDATA, or else certain metal phthalocyanines, in particular such as zinc phthalocyanine (ZnPc), are known as matrix materials having hole transport properties.
However, the previously described compounds have disadvantages for a technical application in the production of doped semiconducting organic layers or of corresponding electronic components comprising doped layers of this type, since the manufacturing processes in large-scale production plants or those on a technical scale cannot always be controlled sufficiently precisely, which results in high control and regulation effort within the processes so as to achieve a desired product quality, or results in undesired tolerances of the products. Furthermore, there are disadvantages in the use of previously known organic doping agents with regard to the electronic component structures, such as light-emitting diodes (OLEDs), field-effect transistors (FETs) or solar cells, since the cited production difficulties encountered when handling the doping agents can lead to undesired irregularities in the electronic components or undesired ageing effects of the electronic components. However, it should be noted at the same time that the doping agents to be used have extremely high electron affinities (reduction potentials) and other properties suitable for the application in question since, for example, the doping agents also co-determine the conductivity or other electrical properties of the organic semiconducting layer under given conditions. The energetic positions of the HOMO of the matrix material and of the LUMO of the doping agent are decisive for the doping effect.
Electronic components comprising doped layers include, inter alia, OLEDs and solar cells. OLEDs are known for example from U.S. Pat. No. 7,355,197 or from US2009051271. Solar cells are known for example from US2007090371 and US2009235971.